Present techniques for providing television commercials have several weaknesses.    1. During television commercials, viewers very often change channels. Unfortunately, this means that the advertiser who is paying to provide the commercials loses its ability to try to sell products to the viewer. This also provides a disadvantage to the viewer, because the program may resume while he is watching something else on the video screen.    2. Commercials use 100% of the television screen space. This means that commercials can only be shown as interruptions of a TV program. The total time duration of such interruptions are regulated. This defines a potential cap on advertisement revenue.    3. The viewer cannot choose to avoid viewing commercials unless he or she changes the channel, in which case he or she may miss portions of the main program. Television viewers consider commercials to be an unavoidable payment for watching television programs. It would be desirable to provide a video system in which the advertiser can still appeal to viewers, while permitting viewers to change channels or use their video systems for other purposes, e.g. web surfing or any other unrelated viewing.